JP2004508681A - Mass gas delivery system for ion implanters - Google Patents

Abstract

A method for delivering gas across a voltage gap in an ion implantation system, particularly a mass gas delivery system for the system, and a gas delivery system and an ion implantation system or other system.
A gas delivery system for an ion implantation system includes a gas source at a first voltage potential and an ion source at a second voltage potential higher than the first voltage potential. Further, the system (100) includes an electrically insulated connector (108) coupled between the gas source and the ion source. The present invention also includes a step (202) of maintaining the source gas potential at a storage location at a first voltage potential lower than the second voltage potential in the ion source of the ion implantation system; and storing the source gas at the storage location. A method of delivering gas to an ion implantation system (200), including delivering (204) from the to the ion source.
[Selection diagram] Fig. 1

Description

[0001]
[Industrial applications]
The present invention relates generally to ion implantation systems, and more particularly to gas delivery systems and methods for delivering gas across voltage gaps in ion implantation systems or other types of devices.
[0002]
[Prior art]
Ion implanters are used to implant or add impurities to silicon wafers to produce n-type or p-type semiconductor materials. The n-type or p-type semiconductor material is used for manufacturing a semiconductor integrated circuit. As the name implies, an ion implanter adds selected ionic species to a silicon wafer to produce the desired semiconductor material. Implanted ions generated from an ion source material such as antimony, arsenic, and phosphorus result in an n-type semiconductor material wafer. On the other hand, if a p-type semiconductor material wafer is desired, ions generated from an ion source material such as boron, gallium or indium will be implanted.
[0003]
The ion implanter includes an ion source for generating positively charged ions from the ionizable material. The generated ions are formed into a beam and accelerated along a predetermined beam path to an implantation station. The ion implanter includes a beam forming and shaping structure extending between the ion source and the implantation station. The beam forming and shaping structure holds the ion beam and defines an elongated internal cavity or area through which the beam passes on its way to the implantation station. When operating an ion implanter, the interior region must be evacuated to reduce the probability that ions will be deflected from a given beam path as a result of collisions with air molecules.
[0004]
For high current ion implanters, the wafers of the implantation station are mounted on the surface of a rotating support. As the support rotates, the wafer passes between the ion beams. Ions flowing along the beam path collide with the rotating wafer and are implanted. The robot arm extracts the wafer to be processed from the wafer cassette and places the wafer in place on the support surface. After processing is complete, the robotics arm removes the wafer from the wafer support surface and reinserts the processed wafer into a wafer cassette.
[0005]
FIG. 1 illustrates a typical ion implanter, generally indicated by reference numeral 10, including an ion source 12 for generating ions forming an ion beam 14 and an implantation station 16. The control electronics 11 is provided for monitoring and controlling the ion dose received by the wafer in the processing chamber 17 of the implantation station 16. Ion beam 14 travels a distance between ion source 12 and implantation station 16.
[0006]
Ion source 12 includes a plasma chamber 18 that defines an interior region into which the ion source material is injected. The ion source material may include an ionizable gas or a vaporization source material. The ion source material in solid form may be deposited into a set of vaporizers 19. Alternatively, a gas source contained in either a high or low pressure vessel may be used. Gaseous hydrogenated arsine (AsH ₃ ) And phosphine (PH ₃ ) Are commonly used as arsenic (As) and phosphorus (P) sources in ion implanters. Due to their toxicity, such gaseous sources are often contained in low pressure SDS (safe delivery system) containers at a short distance from the ion source 12.
[0007]
The ion source material is injected into the plasma chamber and energy is applied to the ion source material to generate charged ions in the plasma chamber 18. The charged ions exit the plasma chamber from the elliptical arc-shaped slit of the cover plate 20 that covers the open side of the plasma chamber 18.
[0008]
The ion beam 14 travels through an evacuation path from the ion source 12 to an implantation station 17 which is also evacuated, for example, by a vacuum pump 21 or the like. The ions in the plasma chamber 18 are extracted from the arcuate slits in the plasma chamber cover plate 20 and accelerated toward the mass analysis magnet 22 by a set of electrodes 24 adjacent the plasma chamber cover plate 20. The plurality of ions forming the ion beam 14 move from the ion source 12 into a magnetic field formed by the mass analysis magnet 22. The mass analysis magnet is part of the ion beam shaping and shaping structure 13 and is maintained in a magnet housing 32. The field strength is controlled by the control electronics 11 by adjusting the current through the field coil of the magnet. The mass analysis magnet 22 causes the ions moving along the ion beam 14 to change to a curved trajectory. Only those ions having the appropriate atomic mass reach the ion implantation station 16. Along the path of the ion beam from the mass analysis magnet 22 to the implantation station 16, the ion beam 14 is further shaped and measured by the voltage drop from the high voltage of the mass analysis magnet housing 32 to the grounded implantation chamber. Accelerated.
[0009]
The ion beam forming and shaping structure 13 additionally includes a quadrupole focusing device 40, a movable Faraday cup 42 and an ion beam neutralizing device 44. The quadrupole focusing device 40 includes a set of magnets 46 disposed around the ion beam 14, which magnets are selected by control electronics (not shown) to adjust the height of the ion beam 14. Is excited. The quadrupole focusing device 40 is housed in a housing 50.
[0010]
Connected to the end of the quadrupole focusing device 40 facing the Faraday flag 42 is an ion beam decomposition plate 52. The resolving plate 52 includes an extension opening 56 through which ions in the ion beam exit the quadrupole focusing device 40. Disassembly plate 52 also includes four counterbore holes 58. Screws (not shown) secure the disassembly plate 52 to the quadrupole focusing device 40. In the resolving plate 52, the ion beam dispersion defined by the width of the range D ', D "is at its lowest value, i.e., the width of D', D" is at the position where the ion beam 14 passes through the resolving plate opening 56. Is the lowest.
[0011]
The resolving plate 52, in conjunction with the mass analysis magnet 22, functions to exclude unwanted ion nuclides from the ion beam 14. The quadrupole focusing device 40 is supported by a support bracket 60 and a support plate 62. The support bracket 60 is connected to the inner surface of the disassembly housing 50.
[0012]
[Problems to be solved by the invention]
As mentioned above, the ion source material is provided to the ion source 12 in a variety of different ways. Since the replacement of solid ion source material is a relatively time consuming process, the use of gas source material is frequently utilized. Because some of the gaseous ion source materials are toxic, unpressurized SDS containers are frequently used to increase leakage safety. These containers are typically stored adjacent to the ion implanter or in a gas steel container integrated with the ion implanter. As a result, replacing the SDS container for the purpose of replenishing the ion source requires access to the clean room where the ion implanter is installed, contributing to machine downtime and potential particle contamination. Therefore, further improvements in existing ion source delivery systems are desired.
[0013]
The present invention relates to a gas delivery system for an ion implanter in which a gaseous ion source material is electrically isolated and / or located remotely from the ion implanter. The ion source material may be remote from the ion implanter, such as a central gas reservoir, and maintained at a first potential, such as ground potential. The gaseous ion source material is then delivered via a gas delivery network to the ion source of the ion implanter at a second potential. The ion source is connected to the ion implanter via an electrically insulated connector. The electrically insulating connector serves as a voltage isolator between a gas storage and / or delivery network provided with a first voltage potential and an ion source of an ion implanter operating at a second voltage potential.
[0014]
[Means for Solving the Problems]
The gas delivery system of the present invention offers various advantages over prior art gas delivery systems. For example, because the gaseous ion source is stored and moved to a remote location, such as a gas store, the machine downtime associated with changing the source material is substantially reduced. In addition, potential particulate contamination from handling the gas enclosure in a clean room is eliminated because ion source material exchange can be performed remotely from the implanter. In addition, the size of the gas box may be significantly reduced since the gas box located adjacent to the ion implanter no longer has individual gas containers (ie, SDS containers).
[0015]
According to a first aspect of the invention, a gas delivery system is disclosed that includes a gas source at a first voltage potential and an ion source at a second voltage potential higher than the first voltage potential. The gas delivery system is further coupled between the gas source and the ion source to promote fluid communication between the gas source and the ion source and electrically isolate the first voltage potential from the second voltage potential. Including electrically insulated connectors.
[0016]
According to another aspect of the invention, a structure for a high voltage isolator for gas delivery is disclosed. The isolator structure includes a first electrically insulated tube surrounded by a second electrically insulated tube in a recessed arrangement. The isolator structure is terminated at each end by an adapter, for example, a stainless steel adapter, and is welded to, for example, a VCR-type fitting. The first tube carries the gaseous ion source material at a first pressure, and the gap between the first and second tubes carries an inert barrier gas at a second pressure different from (ie, higher than) the first pressure. . The isolator structure further includes a monitor port associated therewith where the second pressure is monitored and used to detect leaks associated with the isolator. The structure of the isolator may also be long enough to prevent an arc between the ends, where there is a potential difference between them.
[0017]
According to yet another aspect of the invention, a method for delivering a gas to an ion implantation system is disclosed. The method includes maintaining the source gas at a storage location at a first voltage potential that is lower than a second voltage potential of the ion source of the ion implantation system. The method further includes delivering the source from the storage location to the ion source. This delivery method is achieved, for example, by connecting a high voltage isolator structure between the mass gas transfer system and the ion source. The bulk gas delivery system is maintained at a first potential, eg, a ground circuit, while the ion source is maintained at a second potential, eg, 80 KV. The structure of the isolator allows for storage and exchange of the source material remote from the implantation system, thereby facilitating easy exchange and conversion of the ion source material.
[0018]
With respect to achieving the foregoing techniques and related objects, the invention includes the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. However, these embodiments are merely illustrative of some of the various ways in which the principles of the invention may be used. Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is described herein with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout the specification. The present invention includes systems and methods for delivering an ion source gas from a storage location to an ion source of an ion implantation system when the storage location and the ion source are at different voltage potentials. The system of the present invention includes an ion source gas, such as a pressurized gas, in a gas canister maintained in a storage location remote from the ion implantation system, such as a central gas store. The ion source gas is maintained in a storage location at a potential of a first voltage, for example, a potential of a ground circuit.
[0020]
The ion source gas is then transferred to the ion implantation system through the bulk gas distribution network in a manner similar to gas transfer to other types of processing equipment. Once the source gas is adjacent to the ion implantation system at a second voltage potential (i.e., about 80 KV or more), the gas is forced from the first voltage potential to the second voltage potential. To the gas steel vessel of the ion implantation system via one or more high voltage isolator structures that allow it to be separately increased. Thereafter, the ion source gas is supplied to the ion implanter at a potential of the second voltage as needed. The systems and methods of the present invention allow for remote storage of the source gas at a potential different from that of the ion implantation system, thereby facilitating easy storage, replenishment and replacement of the source gas material.
[0021]
Turning now to the drawings, FIG. 2 is a block diagram illustrating an ion source material delivery system 100 according to exemplary features of the present invention. The delivery system 100 includes a gas storage 102 at a location remote from the ion implantation system, such as outside a clean room where the ion implantation apparatus is located. In accordance with one aspect of the present invention, gas store 102 is a central gas storage location within an assembly facility containing various process gases required for various process steps therein. The gas storage 102 is different from that stored in only a large number of canisters and SDS-based containers, and is different from the processing gas of different types that may be stored in various types of containers such as a pressurized canister. Including storage space. As a result, replacing an empty gas canister can be accomplished by simply disconnecting the canister depending on the application and replacing it with a new one without interrupting gas delivery. According to an exemplary feature of the invention, the process gas in gas reservoir 102 is maintained at a first potential, such as, for example, a circuit ground potential.
[0022]
The delivery system 100 further includes a bulk gas transfer system 104 operatively coupled to the gas reservoir 102 for moving process gas from the gas reservoir 102 to a variety of different processing devices, such as, for example, an ion implantation system. For example, the bulk gas transfer system 104 may include a plurality of gas lines associated with valves, gauges, etc., for distributing process gas from the gas storage 102 to the process equipment. For example, the bulk gas transfer system 104 may have a different source gas there to facilitate easy switching of the ion source gas (ie, enable switching from n-type dopants to p-type dopants). A plurality of different types of ion source gases can be used to deliver from the gas reservoir 102 to the ion implantation system in a manner similar to that possible. The valves, gauges, etc. of the bulk gas transfer system 104 may be used to isolate areas of the gas delivery system, monitor gas line leaks, purge gas lines, etc., depending on the application. According to one exemplary feature of the invention, the gas lines associated with the mass gas transfer system 104 are electrically isolated and pass therethrough at a first voltage potential associated with the gas chamber 102. Operated to maintain gas delivery.
[0023]
Source gas is transferred via the bulk gas transfer system 104 to an exhaust enclosure adjacent and associated with the ion implanter (not shown), sometimes referred to as an ion implanter gas reservoir. In the enclosure or gas steel vessel 106, the ion source gas is ion implanted from a first voltage potential, for example, a circuit ground potential, through a high voltage isolator structure 108 for gas delivery. The potential is raised to a second voltage potential at which the machine operates (ie, about 80 KV). As shown in FIG. 2, one or more isolators (electrically insulated connectors) 108 may be used to couple a variety of different ion source gases to the ion implanter. Thus, the high voltage isolator structure 108 connects the low voltage portion 110a of the gas storage to the high voltage portion 110b in a safe and reliable manner.
[0024]
The high voltage isolator structure 108 stores and maintains a plurality of source processing gases at a convenient potential, such as, for example, a circuit ground potential, and also converts such gases to a plurality of ion sources. It allows convenient storage, for example at high pressure, so that the cost of the gas can be reduced.
[0025]
Although FIG. 2 illustrates a high voltage isolator 108 coupled between two gas chambers at different voltages, other system configurations are also possible and are contemplated to be within the scope of the present invention. ing. For example, there may also be one high voltage gas reservoir associated with the ion implanter, and the isolator structure 108 couples the gas at low voltage from the bulk gas transfer system 104 to the high voltage gas reservoir. good. Alternatively, one gas reservoir may be at a low voltage, such as a ground circuit, and the isolator structure 108 may transfer gas from the low voltage gas reservoir to a high voltage ion source. May be connected.
[0026]
FIG. 3 is an exemplary schematic diagram of a portion of a bulk gas transfer system 104 for use in the system 100 of FIG. The bulk gas transfer system 104 of FIG. 3 illustrates a system that provides four different types of delivery of the source gas, however, a system that provides a greater or lesser number of source gases may also be provided. It may be used and is contemplated to fall within the scope of the present invention. The delivery system 104 includes a set of source gas input conduits 120a-120d that transport the source gas from the gas reservoir 102 to an area within the assembly facility associated with the ion implantation system. The system 104 of FIG. 3 illustrates distribution to only one ion implantation system, however, delivery to multiple ion implantation systems may also be used, and is contemplated to be within the scope of the present invention. Note that
[0027]
Another gas input line 122 is also provided in the delivery system 104 that carries an inert gas, such as nitrogen, for example, through a series of valves 124a-124d to each of a number of lines 120a-120d. I have. The inert gas line 122 is also connected to each of the high voltage isolators 108 via an isolator check valve 126 and check valves 127a to 127d. Further, the inert gas line 122 may include a pressure gauge 128 or an associated monitoring device that may be used to monitor leakage associated with the high voltage isolator 108, as described in more detail below. Having.
[0028]
Illustratively, a more detailed ion source gas delivery system portion 104 'is shown in FIG. Since each of the four conduits 120a-d operates in a similar manner, only one of these conduits will be described for purposes of simplicity and simplicity. The ion source gas line 120a includes an inner gas line 130 surrounded by an outer containment tube 132 that provides safe containment in the event of leakage from the inner gas line 130. In the above method, any potentially toxic or corrosive source gas is safely contained and the inner gas line 130 is structurally protected. Alternatively, the plurality of inner gas lines may be in a single containment tube if preferred. The source gas line 120a is attached to a coupling assembly 134 to which a pressure switch 136 is connected for monitoring / adjusting the source gas pressure. The gas line 120a also includes a valve 121a, such as a pneumatic OP-type valve, that allows specific fluid communication of the ion source gas via the connecting tube 138 to the respective high voltage isolator structure 108.
[0029]
For example, an inert gas, such as nitrogen gas, is supplied through inert gas line 122 and distributed through T-assembly 140. The inert gas may be selectively connected to the connection tube 138 of FIG. 4 through the valve 124a. The manual shut-off valve 126 is also connected to the inert gas line 122 via a connecting tube 142 and a check valve 127a for selectively connecting the inert gas to an outer portion of the high voltage isolator 108.
[0030]
The coupling arrangement may be operated in an exemplary manner as follows. When the source gas is being transferred to the ion implanter, the valve 121a is open, thereby placing the source gas in fluid communication with the high voltage isolator structure 108. At this point, the inert gas supply valve 124a associated with line 120a is closed, thereby preventing the inert gas from diluting the source gas. However, the manual valve 126 has been opened before it to allow the inert gas to enter the high voltage isolator structure 108, for example, into its outer tube. Thus, the source gas in the inner tube of structure 108 is surrounded by an inert gas in the outer tube via valve 126 which has been previously opened. Preferably, the inert gas pressure is greater than the source gas pressure, thereby causing any leakage associated with the inner tube of the structure 108 to cause a leak of the inert gas onto the inner tube, thus exiting the inner tube. To prevent the leakage of potentially corrosive ion source gases. Further, any such leaks may be monitored via a pressure gauge 128, a pressure transducer, or other type of analytical monitoring tool. If the inert gas pressure in line 142 changes (i.e., drops), it is leaking into or out of the inner tube of high voltage isolator structure 108. The inert gas pressure may be monitored by a gauge 128 and a fine regulator (not shown) to help monitor and regulate the operation of various types of valves. For example, the fine-tuner closes valves 121a-121d and detects valves 124a-d when a drop in pressure is detected via pressure gauge 128 (i.e., signifies the destruction of inner containment tube 150 in FIG. 5). Open ~ 124d, thus eliminating dilution of the source gas by the inert gas.
[0031]
Inert gas line 122 may also be utilized to purge the source gas line as needed. In such a case, the ion source gas line valves 121a-121d are closed and the inert gas line valves 124a-124d are opened. The inert gas can then flow through line 138 to the inner tube region of the high voltage isolator structure 108, and thus flush the source gas line at the ion implanter side. Alternatively or additionally, another set of ion source gas line valves (not shown) may be closed and inert gas may be passed through lines 120a-120d to gas reservoir 102. May be returned. In any event, the gas transfer systems 104, 104 'of FIGS. 3 and 4 will cause the ion source gas to be at a first voltage potential, which may be equivalent to the potential at which the source gas is stored in the gas storage 102. It is supplied to the structure 108 of a certain high-voltage isolator.
[0032]
FIG. 5 is a perspective view showing the gas enclosure 106 of FIG. 2 in detail. In particular, FIG. 5 illustrates that one or more high voltage isolator structures 108 may be configured to transfer the source gas from the first portion 110a of the gas enclosure at a first voltage potential (ie, a ground circuit) to a second It may be used to couple to the second portion 110b of the gas enclosure at a voltage potential (ie, the operating potential of the ion implanter). As shown in FIG. 5, a portion of the gas transfer system 104 enters a first portion 110a of the gas enclosure. The source gas enters the inner tube 150 of the high voltage isolator via a coupling 152, such as a VCR-type fitting. Coupling 152 connects to inner tube 150 via metal / insulator transition 154. The inner tube 150 may be, for example, glass, ceramic, quartz, glass / ceramic, to help separate the first potential at one end (first portion 110a) from the second potential at the other end (second portion 110b). Or made of an insulating material such as another dielectric.
[0033]
The high voltage isolator 108 also has a coupling 156 on the other end that allows connection to the ion implanter. The outer tube 158 surrounds the inner tube 150 of the high voltage isolator 108 and is fluidly connected to an inert gas line 142 in which an inert gas having a predetermined pressure flows. As explained above, an inert gas is used to mitigate the negative impact of the leak in inner tube 150, and pressure gauge 128, or other monitoring device, facilitates any such leak. Facilitate monitoring.
[0034]
FIG. 6a illustrates a cross-section of a high voltage isolator structure 108 according to one exemplary aspect of the invention. As briefly described above, the high voltage isolator structure 108 comprises a generally cylindrical inner tube surrounded by a generally cylindrical outer tube portion 162 (corresponding to tube 158 in FIG. 5). It includes an elongated generally cylindrical tube having a portion 160 (corresponding to tube 150 of FIG. 5). Inner tube portion 160 transfers the ion source gas from first end 164 through its second end 166. In particular, the first end 164 terminates in a coupling 168, such as a VCR-type fitting, and connects the high voltage isolator 108 to the gas transfer system 104 in the low voltage portion 110a of the gas enclosure 106. Further, the second end 166 terminates in a coupling 170, such as a VCR-type fitting, and connects the isolator 108 to the ion implanter via the high voltage portion 110b of the gas enclosure 106.
[0035]
Inner tube 160 is made of an electrically insulating material such as, for example, borosilicate glass. However, alternatively, other electrically insulating materials can be used and are contemplated to be within the scope of the present invention. For example, other exemplary materials are aluminum silicate glass, ceramic materials, and the like (ie, Pyrex®, Duran®, Corning® 7740, etc.). May be included, but is not limited thereto. The outer tube 162 surrounds the inner tube 162 in a self-contained arrangement and has a larger diameter than the inner tube, thus defining a gap 172 therebetween. The gap 172 allows the inert gas to flow inside the outer tube 162 and the outside of the inner tube 160, but at a different (ie, greater) pressure than the pressure associated with the source gas in the inner tube 160. In the case where the pressure is maintained, the operation is performed so as to prevent the leakage of the ion source gas from the inner tube 160. Outer tube 162 is also made of, for example, polypropylene, Teflon, or other electrically insulating material.
[0036]
The high voltage isolator 108 of FIG. 6a also includes a port 174 associated with the outer tube 162 that allows an inert gas, such as nitrogen, to be injected into the gap 172, for example, via the gas line 142 of FIG. including. One exemplary port shape is shown in detail in FIG. 6b, which represents an exemplary cross-sectional view of the end 164. Port 174 includes a hole defined by a hole in end cap 178. The hole 176 fits into a tube 180, such as a flexible tube that connects to the inert gas line 142.
[0037]
The gap 172 between the inner tube 160 and the outer tube 162 is sealed by an end cap 178. End cap 178 has an inner lumen 182 that surrounds or engages a glass-to-metal transition piece 184 associated with inner tube 160 and receives a coupling therethrough. The end cap assembly 178 is also fitted and mated with the outer tube 162, end cap 178, and lid 188 to provide a fluid tight seal to prevent leakage associated with the high voltage isolator 108. Includes one or more O-rings that operate. Alternatively, these parts may be welded together.
[0038]
The high voltage isolator 108 operates to facilitate raising the voltage of the ion source gas from a first potential to a second potential. For example, the ion source gas may be stored in the gas chamber 102 at the ground potential of the circuit and moved to the first portion 110a of the gas enclosure 106 of the ion implanter at the stored potential (ie, the first potential). Since the ion implanter operates at a high voltage (ie, about 80 KV), the high voltage isolator 108 allows the ion source gas to safely and reliably raise the ion implanter operating voltage (ie, the second potential). To provide a structure. According to one exemplary feature of the invention, the high voltage isolator 108 is long enough to withstand the potential difference that exists across its ends 164, 166 without having an arcuate shape therebetween. A general rule of thumb is to allow a length of about one inch for each potential difference of about 10 KV. Therefore, if an approximately 80 KV potential difference exists between the ends 164, 166, it may be desirable to have a length of about 8 inches or more. However, any length that prevents the arc shape may be utilized and is contemplated to be within the scope of the present invention.
[0039]
In accordance with another aspect of the present invention, a method for delivering an ion source gas to an ion implantation system is illustrated in FIG. 7 and disclosed as identified by reference numeral 200. The method 200 includes maintaining the source gas at a storage location at a first voltage potential 202 and thereafter delivering the ion source gas to an ion source 204 at a second voltage potential. For example, the source gas may be stored in the gas chamber 102 of FIG. 2 at circuit ground potential and then delivered to the ion source of the ion implantation system operating at a high voltage (ie, about 80 KV).
[0040]
According to one exemplary feature of the present invention, delivering the ion source gas may be performed according to the flowchart of FIG. The source gas is transferred from its storage location to a gas enclosure associated with the ion implantation system using, for example, the bulk gas transfer system 104 of FIG. 2 and, at step 206, the structure of the high voltage isolator. (Ie, structure 108 in FIGS. 6a and 6b). The high voltage isolator is coupled to the ion source of the implantation system, which provides for the transfer of the ion source gas therethrough to the ion implantation system at step 208. High voltage isolators transfer the potential of the source gas in a safe and reliable manner, typically to an ion implantation system, such as in a system gas enclosure (ie, gas enclosure 106 of FIG. 2). At an adjacent position, it facilitates raising from the first potential to the second potential.
[0041]
Source gas delivery may be monitored at step 210 to ensure that gas delivery is not continued under leaky system conditions. For example, the high voltage isolator may be arranged in a manner similar to the structure 108 of FIGS. 6a and 6b where the outer tube containing the inert gas surrounds the inner tube. The outer tube inert gas is then maintained at a higher pressure than the inner tube ion source pressure. As a result, if there is any leakage associated with the inner tube, the source gas will be contained therein. By monitoring the pressure of the inert gas in the outer tube, a leak is detected if the pressure drops, for example, if the pressure drops below a predetermined threshold.
[0042]
If the pressure falls below a predetermined threshold, a determination is made that there is a leak associated with the isolator structure. Source gas transfer is then aborted at step 212 based on the determination, such as by closing a transfer valve associated with the bulk gas transfer system 104 of FIG.
[0043]
While the invention has been shown and described with respect to precise embodiments, it will be apparent to those skilled in the art, upon reading and understanding the present specification and the accompanying drawings, that similar modifications and changes will occur. Will. In particular, with respect to various functions performed by the components described above (assemblies, devices, circuits, systems, etc.), the terminology used to describe such components (see "means") ), Unless otherwise stated, perform a function in the illustrated exemplary embodiment of the invention, even if it is not structurally equivalent to the disclosed structure. It is intended to correspond to any component (ie, functionally equivalent) that performs a particular function of the illustrated component. Moreover, while particular features of the invention may be disclosed in connection with only one of the embodiments, such features are required for any particular or special application, and advantages may be realized. If so, it may be combined with one or more other features of other aspects. Further, with respect to the terms “comprising,” “including,” “having,” “having,” and variations to the extent that those variations are used in the description or the claims, these terms include the terms “includes” It is intended to encompass the equivalent of "".
[0044]
(Industrial applicability)
The systems and methods of the present invention may be used in the field of semiconductor processing, such as ion implantation, which provides safe, effective and economical source gas delivery to an ion implantation system.
[Brief description of the drawings]
FIG.
FIG. 3 is a diagram showing a conventional horizontal diagram in an ion implantation system.
FIG. 2
1 is a block diagram illustrating a delivery system for an ion source material according to one exemplary aspect of the invention.
FIG. 3
FIG. 2 is a schematic diagram illustrating a portion of an ion source gas delivery module maintained at a first voltage potential according to one aspect of the present invention.
FIG. 4
FIG. 4 is a schematic diagram illustrating a portion of the ion source gas delivery module of FIG. 3 according to one aspect of the present invention.
FIG. 5
FIG. 2 is a composite perspective view and schematic diagram illustrating a structure of a plurality of high voltage isolators coupled between two exhaust enclosures maintained at different potentials according to one aspect of the present invention.
FIG. 6a is a cross-sectional view illustrating a structure of a high voltage isolator according to one aspect of the present invention.
6b is a cross-sectional view illustrating an end portion of the structure of the high-voltage isolator of FIG. 6a in accordance with one aspect of the present invention.
FIG. 7 is a flowchart illustrating a method of delivering an ion source material to an ion implantation system according to one aspect of the present invention.
FIG. 8 is another flow diagram illustrating a method of delivering an ion source gas from a storage position to an ion source when the storage position and the ion source position are maintained at different voltage levels according to the present invention.

Claims (26)

A gas delivery system (100) for an ion implantation system, comprising:
A gas source (102) at a potential of a first voltage;
An ion source at a second voltage potential greater than the first voltage potential;
A gas delivery system comprising an electrically insulated connector (108) connected between the gas source and the ion source. The system of claim 1, wherein the potential of the first voltage is configured as a circuit ground potential. The system of claim 1, wherein the gas source supplies a pressurized gas. The system of claim 1, wherein the electrically insulated connector (108) includes a first electrically insulated tube (150, 160). The system of claim 4, wherein the first electrically insulating tube (150, 160) comprises borosilicate glass, aluminum silicate glass, quartz, or a ceramic material. The electrically insulated connector (108) further includes a second electrically insulated tube (158, 162) fitted outside of the first electrically insulated tube, the inset arrangement providing a gap (172) between the tubes. The system of claim 4, wherein the system is formed to facilitate delivery of pressurized gas within the gap (172). The gas pressure in the gap (172) is greater than the gas pressure in the first electrically insulated tube, thereby allowing gas from the first electrically insulated tube (150, 160) to enter the gap (172). 7. The system according to claim 6, wherein the system prevents leakage. A pressure monitoring device (128) coupled to a port associated with the second electrically insulating tube (158, 162), wherein the pressure monitoring device (128) detects a change in pressure in the gap. The system of claim 7, wherein the system is operable. A safety controller associated with the pressure monitoring device (128), wherein the safety controller disconnects a gas source from the electrically insulated connector (108) based on pressure information provided by the pressure monitoring device (128). 9. The system of claim 8, wherein the system is capable of: The gas pressure in the gap (172) is different from the gas pressure in the first electrically insulating tubes (150, 160) and further includes a monitor connected to the electrically insulated connector (108). The system of claim 6, wherein a monitoring device (128) is operable to detect a leak associated with the electrically insulated connector (108). The electrical insulation connector (108) includes a plurality of high voltage isolators for gas delivery, each of these isolators further comprising:
Inner extension tubes (150, 160) for allowing the transfer of gas from the gas source to the ion source;
The inner extension tubes (150, 160) include an outer extension tube (158, 162) which is disposed in a self-contained manner,
The recessed arrangement forms a gap (172) between the inner extension tube (150, 160) and the outer extension tube (158, 162), respectively, and includes an inert protective gas in the gap (172). The system of claim 1, wherein the system is configured to: Each of the isolators is configured to move a different gas than the gas in the other isolators, thereby facilitating quick switching of the supply gas from the ion source. The system according to claim 11. A first exhaust enclosure (110a) surrounding each first end of the isolator and connected to an ion source; and a second exhaust enclosure (110a) at each second end of the isolator and connected to the ion source. An exhaust enclosure (110b), wherein each of the first exhaust enclosures (110a) is maintained at a potential of the first voltage, and a second exhaust enclosure (110b) is configured to maintain a potential of the second voltage. The system of claim 11, wherein the system is maintained at an electrical potential. A valve device (121, 124, 138) coupled to the first and second exhaust enclosures (110a, 110b);
The first and second exhaust enclosures each release, in a first configuration, a source gas in a first direction toward the gas source, and in a second configuration, toward the ion source. 14. The system of claim 13, wherein the system is configured to emit the source gas in a second direction. A method (200) for delivering a gas to an ion implantation system, comprising:
Maintaining a potential at a storage location at a first voltage potential that is lower than a second voltage potential at the ion source of the ion implantation system (202);
Delivering a source gas from the storage location to the ion source (204). The method of claim 15, wherein the stored source gas is pressurized. The method of claim 15, wherein the potential of the first voltage is substantially the potential of a ground circuit. The method of claim 15, wherein the potential of the second voltage is about 80 KV. Delivering the stored source gas (204) comprises:
Engaging a valve device such that the source gas flows in the direction of the ion source via a gas transfer system at a potential of the first voltage;
16. The method of claim 15, including coupling the gas transfer system to the ion source via a high voltage isolator. Connecting the gas transfer system to the ion source via the high voltage isolator,
Connecting a first end of the high voltage isolator to the gas transfer system, wherein the first end is at a first voltage;
20. The method of claim 19, further comprising coupling a second end of the high voltage isolator to the ion source, wherein the second end is at a potential of a first voltage. The high voltage isolator includes a first electrically insulating tube (150, 160) having a length sufficient to withstand a predetermined voltage which is a potential difference between the first voltage potential and the second voltage potential. 20. The method of claim 19, wherein: The high voltage isolator further includes a second electrically insulated tube (158, 162), the second insulated tube (158, 162) being the same as the first electrically insulated tube (150, 160). 22. The method according to claim 21, characterized in that it is arranged in a telescoping manner, said telescoping arrangement forming a gap (172) between the tubes. Delivering the source gas from the storage location to the ion source,
Transferring a source gas at a first pressure into the first electrically insulating tubes (150, 160);
Transferring the inert gas into the gap (172) between the first and second electrically insulating tubes at a second pressure greater than the first pressure;
23. The method of claim 22, which prevents the source gas from leaking into the gap. Monitoring the second pressure of the inert gas in the gap (172) (210), whereby a leak is detected when the second pressure falls below a predetermined threshold pressure. The method of claim 23, wherein: 20. The method of claim 19, further comprising purging the high voltage isolator in a first direction, wherein the source gas is exhausted from the gas transfer system. 20. The method of claim 19, further comprising purging the high voltage isolator in a second direction, wherein the source gas is exhausted from a region proximate to the ion source.

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